1. Technical Field of the Invention
This application claims priority under 35 U.S.C. .sctn..sctn. 119 and/or 365 to Patent Application No. 98-02416 filed in France on Feb. 27, 1998; the entire content of which is hereby incorporated by reference.
The present invention relates to novel cosmetic and/or dermatological compositions which are intended more particularly for photoprotecting the skin and/or the hair against ultraviolet radiation (these compositions being referred to more simply hereinbelow as antisun compositions), as well as to their use in the abovementioned cosmetic application. Even more specifically, the invention relates to antisun compositions comprising, in a cosmetically acceptable support, a combination between a first specific screening agent, i.e. a specific 1,3,5-triazine derivative, with at least a second specific screen agent suitably selected from benzotriazole silicones, this combination giving the said compositions, by means of a synergistic effect, improved sun protection factors.
2. Description of the Prior Art
It is known that light radiation with wavelengths of between 280 nm and 400 nm permit tanning of the human epidermis and that rays with wavelengths of between 280 and 320 nm, which are known as UV-B, cause erythema and skin burns which may be harmful to the development of a natural tan; this UV-B radiation should thus be screened out.
It is also known that UV-A rays, with wavelengths of between 320 and 400 nm, which cause tanning of the skin, are liable to induce an adverse change therein, in particular in the case of sensitive skin or skin which is continually exposed to solar radiation. UV-A rays in particular cause a loss of skin elasticity and the appearance of wrinkles, leading to premature ageing. They promote triggering of the erythemal reaction or amplify this reaction in certain individuals, and may even be the cause of phototoxic or photoallergic reactions. It is thus desirable also to screen out UV-A radiation.
Many cosmetic compositions intended for photoprotecting the skin (against UV-A and/or UV-B) have been proposed to date.
These antisun compositions are quite often in the form of an emulsion of oil-in-water type (i.e. a cosmetically acceptable support consisting of an aqueous dispersing continuous phase and an oily dispersed discontinuous phase) which contains, in various concentrations, one or more standard, lipophilic and/or hydrophilic organic screening agents capable of selectively absorbing harmful UV radiation, these screening agents (and the amounts thereof) being selected as a function of the desired protection factor (SPF), which is expressed mathematically by the ratio of the irradiation time required to reach the erythema-forming threshold with the UV screening agent to the time required to reach the erythema-forming threshold without a UV screening agent.